A 25-year-old man is accused of sexually assaulting four young children, who kept the abuse quiet for some time out of fear he would hurt them.

Michael James Roberts forced three girls and one boy into various sex acts on different occasions, according to a Pasco County Sheriff's Office report. It's unclear when the alleged incidents occurred, but the victims said they were 7 to 9 years old at the time. The boy told deputies he was abused several times over the span of a year and a half, and that Roberts "threatened to kill him if he did not perform these acts," the report said.

Roberts, of Land O'Lakes, declined to talk to detectives when he was arrested Tuesday. He was charged with four counts of sexual battery, and remained Wednesday at the Land O'Lakes jail without bail.